CVE-2026-90583: Software Security Vulnerability Vulnerability

MODERATE
Advisory Identifier: GHSA-4mhr-77m9-cfv9
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CVSS 4.3
CWE-79
Published
Advisory Summary

CVE-2026-90583 is a MODERATE (CVSS 4.3) security vulnerability vulnerability (CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')) affecting Software libraries in the Maven ecosystem. The weakness occurs when the product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.. Remediation is available in the latest vendor maintenance releases.

CVE-2026-90583 at a Glance

CVE Identifier CVE-2026-90583
GHSA Identifier GHSA-4mhr-77m9-cfv9
Severity MODERATE
CVSS v3.1 Base Score 4.3
CWE Classification CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Affected Product Software
Package Ecosystem Maven
Published Date
Last Updated

Security Impact

CVSS: 4.3

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required None (PR:N)
User Interaction Required (UI:R)
Scope Unchanged (S:U)
Confidentiality None (C:N)
Integrity Low (I:L)
Availability None (A:N)

How to Fix CVE-2026-90583

To remediate this vulnerability, upgrade all affected Software dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

mvn dependency:tree

How to Check if You Are Affected

To determine whether your Java application is affected by CVE-2026-90583, inspect your build dependencies using the Maven Dependency Plugin:

mvn dependency:tree

Analyze the terminal output to locate any version of Software in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than the patched release), your application is affected.

Note: The mvn dependency:tree command inspects the resolved dependency graph declared in your project's POM files; it does not perform automated security scanning or inspect runtime dynamic classpaths. Always verify runtime container classpaths and shaded JARs.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting'), where the product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users. In Software, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

A security flaw has been discovered in kagisearch smallweb up to 0ecb9c48edbf98dc7e934b54fbac43869e64b4cf. The affected element is the function index of the file app/sw.py of the component Query String Rendering. Performing a manipulation of the argument qs results in cross site scripting. The attack is possible to be carried out remotely. This product adopts a rolling release strategy to maintain continuous delivery. Therefore, version details for affected or updated releases cannot be specified. The patch is named 00b68144e583f20a6b67e29cf01bc07f57979ffb. It is recommended to apply a patch to fix this issue. Exploitability requires a raw HTTP request carrying unencoded double-quote characters in the query string - Werkzeug's request.query_string returns the raw request-target, and ordinary browsers percent-encode " as %22, so the payload only lands via netcat/curl-style raw sockets.

References

NVD — CVE-2026-90583 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-90583
Software Source Repository REPOSITORY
https://github.com/kagisearch/smallweb/issues/854
Security Fix Commit FIX COMMIT
https://github.com/kagisearch/smallweb/commit/00b68144e583f20a6b67e29cf01bc07f57979ffb
Software Source Repository REPOSITORY
https://github.com/kagisearch/smallweb
vuldb.com/cve/cve-2026-90583 WEB
https://vuldb.com/cve/CVE-2026-90583
vuldb.com/submit/913779 WEB
https://vuldb.com/submit/913779
vuldb.com/vuln/403168 WEB
https://vuldb.com/vuln/403168
vuldb.com/vuln/403168/cti WEB
https://vuldb.com/vuln/403168/cti

Frequently Asked Questions

What is CVE-2026-90583?
CVE-2026-90583 is a security vulnerability in Software classified as a security vulnerability vulnerability under CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting').
Which Software versions are affected?
Affected versions include releases prior to current release patches.
What version fixes CVE-2026-90583?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
What is the CVSS score of CVE-2026-90583?
CVE-2026-90583 has a CVSS v3.1 base score of 4.3 (MODERATE) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N.
What CWE is associated with CVE-2026-90583?
CVE-2026-90583 is classified under CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') (The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.).
How can I check Maven dependencies for CVE-2026-90583?
Run the dependency tree command: 'mvn dependency:tree'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
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  "aliases" : [ "CVE-2026-90583" ],
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